The Western Design Center, Inc.

W65C02S Data Sheet

The Western Design Center, Inc.

W65C02S Data Sheet

17

4.4

Absolute Indexed with Y a, y

With the Absolute Indexed with Y addressing mode, the Y Index Register is added to the second and third bytes of the

instruction to form the 16-bit effective address.

Byte:

2

1

0

Instruction:

ADH

ADL

OpCode

ADH

ADL

+

Y

Operand address:

effective address

4.5

Absolute Indirect (a)

With the Absolute Indirect addressing mode, the second and third bytes of the instruction form an address to a pointer. This

address mode is only used with the JMP instruction and the Program Counter is loaded with the first and second bytes at this

pointer.

Byte:

2

1

0

Instruction:

ADH

ADL

OpCode

Indirect address:

ADH

ADL

New PC value:

indirect address

4.6

Accumulator A

With Accumulator addressing the operand is implied as the Accumulator and therefore only a single byte forms the

instruction..

Byte:

2

1

0

Instruction:

OpCode

Operand:

accumulator

4.7

Immediate Addressing #

With Immediate Addressing the operand is the second byte of the instruction.

Byte:

2

1

0

Instruction:

Operand

OpCode

Operand:

Operand

4.8

Implied i

Implied addressing uses a single byte instruction. The operand is implicitly defined by the instruction.

Byte:

2

1

0

Instruction:

OpCode

Operand address:

implied